High-voltage sparker for self-supporting cable with bare messenger



Patented Apr. 14, 1953 mom oLr-A E, S ARKER; FOR LFYY- U H l PORTI-NG: CABLE WITH BARE MESSENGER Edward K.- may, Rome, N; Y.-, assignor to Rome Cable corporation, Rome; Y., a corporation of New York Application February 9, 1951, Serial No. 210,256

tral uninsulated conductor which acts as a supporting messenger. It has been impossible to spark test this type cable. during manufacture with the apparatus heretofore available because a bare messengerin passing through the sparker apparatus heretofore available would immediately ground any applied voltage.

7 Accordingly it is an object of this invention to provide method and apparatus for spark testing self-supportin type cable.

the take-up stand or reel E4, the ends of said 6'- Claims. (01. 1 75-483) l 2 cable being grounded at said reels respectively, as indicated at It and I8. v

An assembly, comprising an insulating tube 28 and the annular collars or end disks 22 and 24 fitting over the ends respectively of tube 20 is mounted between the pillow blocks 26 and 28 in which respectively the end disks 22 and 24 of said assembly are received and rotatably supported. The pillow blocks are connected to ground as indicated in Figure at 30 and 32. The annular end disks 212and 24 have the lat erally extending flanges 22 and 24 respectively through which set screws 34 extend to fasten said end disks on the tube. The ends of the tube are Another object of the invention is to provide fl h With e 0 ends of d end d S a spark testing apparatus through which cabl of the uninsulated conductor Hi is led in a straight .the self-supporting type may be continuously line directly through the tube. Between the cenpassed without disturbing the twist or lay of the 1' p n ng Of said end disks 22 and 2 throu h insulated conductors. which tube 26 extends and the outer periphery Another object of the invention is to provide of said end disks respectively pairs f l s 36 means for i'nsulating the bare messenger of selfand 3?, and 38 and 39 respectively are disposed supporting type cable while impressing a high ide by s an extending parallel to e tub voltage on insu'lated conductor means twisted so that. both insulated conductor [0 which is around said messenger. ledthrough holes 36 and 38 successively and conb other objects of the invention 111 be i rt ductor Hi which is led through holes 31 and 39 obvious or in part pointed out hereinafter, successively, extend over and around the exterior The invention accordingly consists in the feaufie 0f tube tures of construction, oonibinationsof elements, Preferably e p w b Ocks 26 and 28 are arrangements of parts, and in the several steps fi l 'd apart a distance equal to the y f the and relation and order or each r said steps to cabl so h each Of Said insulated conductors one or more of theother's thereof, all as will be '3" and It make one comp e r around the pointed out in the following description, and the exterior Surface of s lat n u e 20 in pas ing scope of the application or which will be indicated between Said end disks 22 n It i thlis in the following claims. 5 that 7 F1 ca l is a n the The invention will best be understood if the p a Winding of wnd and W 1 following description is read in connection with causethe s m of the insulating tube 25 and the drawings, in which the end disks 22 and 24 to revolve in accordance igure 1 is a perspective view of an embodiment w 'fih the cable If 1t .5 d e tog test of the device; cablfsbofldiflerent lay oitie end (grist: inday be 1100?- a r one y ooseningi sse screw ,an angu ary E Figure 2 1s Yertml cmss Sectlon taken the revolved relative to the other end disk as much no 22 of Figure 1; as is rquired;

1 figure 3 f v r m cross seamen taken on e Surrounding said insulating tube 25 are one or l1ne 33 of F1gure 1; 'more rings 40 of conductive material. Either a Figure 4 is an enlarged longitudinal cross secnumber of narrow rings spaced apart as shown, tion of the left hand end of Figure 1; and "01 a single continuous tubular member may be Figure 5 is a diagrammatic plan view. employed The assembly of insulating tube 20 In the embodiment of the invention shown and end disks 22 and 24 and the insulating rings herein a'length of self-supporting type cable In, A!) surrounding tube 26 intermediate the guide comprising, an uninsulated conductor or messenplates, extends in close proximity to a high voltger w and the insulated conductors It and It age electrode. As shown herein this assembly respectively spiralled around said uninsulated extends through an electrode 42 which is tubular wconductor or messenger Ill is shown extending inform when closed and comprises two semibetween a pay-off stand or reel l2 (Figure 5) and circular portiens tzaa d. ag ifi th i the hinges h, the portion 52 being supported on the insulating standards 43 and the portion 42 having a number of chains i l extending across it transversely and connected at their ends along the respective longitudinal margins of said electrode part. The chains M are long enough to form loops hangin down into the interior of the electrode and yieldingly contacting and extending partly around the surface of the portions of the insulated conductors iii and Ill passing through said electrode, and also contacting the conductive ring or rings til. High voltage is supplied to the electrode through lead 6 from any suitable source, and it will be understood that this high voltage is transmitted to said ring or rings 46 through contact between said ring or rings and one or more of said chains 44. The insulated conductors it? and through the electrode and travelling over and around insulating tube as, pass over conducting ring or rings 4t and between said ring or rings and the chains 46 of the electrode device. Thus high voltage is impressed by the chains 44 on and around a more or less semi-circular portion or the insulation of said conductors It and 13, and high voltage is impressed upon a portion of the surface of said conductors lil and N opposite to said semi-circular portion by contact with said conducting rin or rings it. Thus the high voltage is impressed substantially over the entire insulation surface of the conductors It? and [0 and any faults in the insulation cause sparking i. e. bridging of the distance between a high voltage contact (chains M or ring or rings it) and the core of the conductor, which may be detected and recorded in a Well known manner.

By the method disclosed herein self-supporting type cable may, for the first time, be spark tested. The apparatus disclosed herein provides preferred means for carrying out the method, which is novel and fills a long existing need.

It will thus be seen that there has been providedby this invention a method and apparatus in which the various objects hereinabove set forth together with many thoroughly practical advantages are successfully achieved. As various possible embodiments might be made of the'mechanical features of the above invention and as the art herein described might be varied in various parts, all without departing from the scope of the invention, it is to be understood that all'matter hereinbefore set forth or shown in the accompanying drawing is to be interpreted as illustrative and not in a limiting sense.

What I claim is:

1. Apparatus for spark testing the insulation of the insulated conductors of a self-supporting cable having an uninsulated conductor and one or more insulated conductors wound spirally around said uninsulated conductor, without untwisting the insulated conductor or conductors, which comprises, a pair of rotatable guide means each having a. central aperture 01 a size to receive said uninsulated conductor, and one or more other apertures radially related to said central aperture, and of a size to receive said one or more insulated conductors, said guide means being positioned in spaced relation with their said central apertures in alignment, and support means for said guide means respectively, an insulating tube positioned between said guide means and aligned axially with the said central apertures of said guide means, an electrode having yielding contact members extending into close proximity with the said external surface of said insulating tube, and means to continually advance said cable,

6 in passing.

whereby said uninsulated conductor may be continuously passed through the central aperture in said guides and through said insulating tube, and said one or more insulated conductors may be continuously passed through the said other apertures of said guide means respectively, over and spirally around the external surface of said insulating tube and into contact with the said yielding contact members of said electrode. 7

2. Apparatus for spark testing the insulation of the insulated conductors of a self-supporting cable having an uninsulated conductor and one or more insulated conductors wound spirally around said uninsulated conductor, without untwisting the insulated conductor or conductors, which comprises, a pair of rotatable guide means each having a central aperture through which said uninsulated conductor may be passed and one or more other apertures radially related to said central aperture, through which said one or more insulated conductors may be passed, said guide means being positioned in spaced relation with their said central apertures in alignment, and support means for said guide means respectively, an insulating tube positioned between and rotatable with said guide means and aligned axially with the said central apertures of said guide means, an electrode having yielding contact members extending into close contact with the said external surface of said insulating tube, and means to continually advance said cable, said insulating tube having on its external surface a conductive area in contact with the said yielding contact members of said electrode.

3. The method of testing a cable comprising one or more insulated conductors wound spirally around and supported by a bare messenger which comprises, supporting the insulated conductor or conductors by passing them individually through a plurality of spaced apart, aligned, rotatable support means, continuously advancing said cable through said support means and employing the twist of said insulated conductor or conductors to rotate said support means, interposing insulating shield means between said insulated conductor or conductors and said bare messenger'during the travel of said cable between said support means, and subjecting the insulated conductor or conductors to a spark test while separated from the bare messenger by said insulating shield means.

4. The method of testing a cable comprising one or more insulated conductors twisted around and supported by a bare messenger without untwisting the cable which comprises, continuously advancing the cable and throughout a portion of its travel separating the insulated conductor or conductors from the bare messenger While rotating the cable in accordance with the lay of said insulated conductor or conductors by passing the insulated conductor or conductors and the bare messenger individually through spaced and rotatable support means, interposing an insulating member between said insulated conductor or conductors and said bare messenger and rotating said insulating member in accordance with the lay of said insulated conductor or conductors, and subjecting the insulated conductor or conductors to a spark test while separated from the bare messenger by said insulating member.

5. Apparatus for locating faults in the insulation of a cable comprising one or more insulated conductors spiralled around a bare messenger which comprises, an insulating tube and rotatable guide means for said insulated conductors positioned respectively to direct said bare messenger through said insulating tube and said in-' 6 6. The apparatus claimed in claim 5 in which said insulating tube is also rotatable and means are provided for rotating it in synchronism with the rotation of said rotatable guide means.

EDWARD K. DUFFY.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,952,582 Cary et a1 Mar. 27, 1934 2,488,578

Boynton et al Nov. 22, 1949 

